PDA

View Full Version : New tonearm for AR XA: suggestions?


Antti Nayha
August 8th 03, 03:43 PM
Hi all,

my trusty old AR XA turntable (purchased in 1970) needs some
refurbishing. In particular, the tonearm is so worn out that
I just can't get the adjustments right any more.

Now, I found some nice L.A. Audio File articles from the 80's
about modifying AR's: http://www.laaudiofile.com/backissu.html
The last article has excellent instructions for choosing and
refitting a modern tonearm. Quote:

The preferred tone arm for the AR mod is one that
mounts via a threaded pillar with a locking nut. Both
the Mayware Formula 4 and Grace 707 Mark II meet this
requirement. Unfortunately, my classic favorite, the
SME 3009 Mark II Improved, does not.

The springs on the I-bar subchassis are carefully
spaced equidistance from its center of gravity. So,
ideally, the replacement arm should be the same weight
as the original. I found that the original tone arm
and its spindle well (after removal) come to about 7
oz. Ideally, the replacement arm and its mounting
plate should come close to that figure. Another
important specification is the tone arm length - the
original arm has a 9" stylus to pivot length, and is
11 5/8" overall. You should, of course, be sure the
counterweight of the replacement arm will clear the
corner of the dust cover.

The problem is, since the article is 15 years old, both of the
two suggested tonearms are quite hard to find (and expensive!)
nowadays. I'd be grateful for any suggestions for other
suitable replacement arms, preferably cheap ones... or, at
least ones with good value for money. :-)

--
Antti

Fill X
August 9th 03, 05:37 AM
I'd say the grace arm is about right for the table, anything better might be
worth a better table. The premier arm is good for that table too as I recall.
The arm was really weak on the AR table.

P h i l i p

______________________________

"I'm too ****ing busy and vice-versa"

- Dorothy Parker

Kalman Rubinson
August 9th 03, 07:48 AM
The best replacement articles actually re-engineered the subchassis.
Considering the complications of a non-adjustable suspension that
might, itself, be on their way towards failure, I'd suggest replacing
the whole thing with one of the similar Thorens TTs (from the 150 to
the present) that have adjustable springs and a replaceable armboard.

Kal

On 8 Aug 2003 14:43:43 GMT, Antti Nayha > wrote:

>Hi all,
>
>my trusty old AR XA turntable (purchased in 1970) needs some
>refurbishing. In particular, the tonearm is so worn out that
>I just can't get the adjustments right any more.
>
>Now, I found some nice L.A. Audio File articles from the 80's
>about modifying AR's: http://www.laaudiofile.com/backissu.html
>The last article has excellent instructions for choosing and
>refitting a modern tonearm. Quote:
>
> The preferred tone arm for the AR mod is one that
> mounts via a threaded pillar with a locking nut. Both
> the Mayware Formula 4 and Grace 707 Mark II meet this
> requirement. Unfortunately, my classic favorite, the
> SME 3009 Mark II Improved, does not.
>
> The springs on the I-bar subchassis are carefully
> spaced equidistance from its center of gravity. So,
> ideally, the replacement arm should be the same weight
> as the original. I found that the original tone arm
> and its spindle well (after removal) come to about 7
> oz. Ideally, the replacement arm and its mounting
> plate should come close to that figure. Another
> important specification is the tone arm length - the
> original arm has a 9" stylus to pivot length, and is
> 11 5/8" overall. You should, of course, be sure the
> counterweight of the replacement arm will clear the
> corner of the dust cover.
>
>The problem is, since the article is 15 years old, both of the
>two suggested tonearms are quite hard to find (and expensive!)
>nowadays. I'd be grateful for any suggestions for other
>suitable replacement arms, preferably cheap ones... or, at
>least ones with good value for money. :-)

whifhi
August 9th 03, 07:15 PM
How about just using an ebay AR 'table for needed parts? Granted the
AR arm isn't on par with good separate arms, but it *did* manage to
acceptably function for you for 30 years! And who's to say that you'll
be happy with your Frankentable when you've finished modding it with a
20 year-old Grace? Bring your trusty AR back to life, and save the
experiments for something that's let you down!

Antti Nayha > wrote in message >...
> Hi all,
>
> my trusty old AR XA turntable (purchased in 1970) needs some
> refurbishing. In particular, the tonearm is so worn out that
> I just can't get the adjustments right any more.
>
> Now, I found some nice L.A. Audio File articles from the 80's
> about modifying AR's: http://www.laaudiofile.com/backissu.html
> The last article has excellent instructions for choosing and
> refitting a modern tonearm. Quote:
>
> The preferred tone arm for the AR mod is one that
> mounts via a threaded pillar with a locking nut. Both
> the Mayware Formula 4 and Grace 707 Mark II meet this
> requirement. Unfortunately, my classic favorite, the
> SME 3009 Mark II Improved, does not.
>
> The springs on the I-bar subchassis are carefully
> spaced equidistance from its center of gravity. So,
> ideally, the replacement arm should be the same weight
> as the original. I found that the original tone arm
> and its spindle well (after removal) come to about 7
> oz. Ideally, the replacement arm and its mounting
> plate should come close to that figure. Another
> important specification is the tone arm length - the
> original arm has a 9" stylus to pivot length, and is
> 11 5/8" overall. You should, of course, be sure the
> counterweight of the replacement arm will clear the
> corner of the dust cover.
>
> The problem is, since the article is 15 years old, both of the
> two suggested tonearms are quite hard to find (and expensive!)
> nowadays. I'd be grateful for any suggestions for other
> suitable replacement arms, preferably cheap ones... or, at
> least ones with good value for money. :-)

Gene Poon
August 10th 03, 03:31 PM
Kalman Rubinson wrote:

> The best replacement articles actually re-engineered the subchassis.
> Considering the complications of a non-adjustable suspension that
> might, itself, be on their way towards failure, I'd suggest replacing
> the whole thing with one of the similar Thorens TTs (from the 150 to
> the present) that have adjustable springs and a replaceable armboard.
>
===============================

No need; it's not as though the suspension is about to "fail" anyway;
the parts in an AR Turntable suspension are very durable. And it is not
really non-adjustable; it is only so if you don't remove the bottom
plate and adjust it! The process is no different from adjusting a Linn
Sondek suspension, actually.

My "fun" turntable is an old AR-XA; so old, it still had the second
starting motor, whose belt I have removed, and which I disconnected
electrically. So modified, the flutter is lower but the platter has to
be started in the correct direction with a push, after the power is
turned on! The arm is an adaptation of the Well Tempered design,
homebuilt and fitted onto a post which fits into the original AR tonearm
shaft well. The suspension was then leveled to match the weight of the
arm assembly. It does help if one damps out resonances in the
subchassis by filling the cavities on its bottom side with modeling
clay! The arm has proven to work well with many different cartridges,
the current one being a Decca Super Gold; the arm's damping does seem
effective in taming some of the Decca's quirks!

-Gene Poon

Kalman Rubinson
August 12th 03, 03:16 AM
There's an AR arm on eBay right now that might make it easy for you.

Kal

On 8 Aug 2003 14:43:43 GMT, Antti Nayha > wrote:

>Hi all,
>
>my trusty old AR XA turntable (purchased in 1970) needs some
>refurbishing. In particular, the tonearm is so worn out that
>I just can't get the adjustments right any more.
>
>Now, I found some nice L.A. Audio File articles from the 80's
>about modifying AR's: http://www.laaudiofile.com/backissu.html
>The last article has excellent instructions for choosing and
>refitting a modern tonearm. Quote:
>
> The preferred tone arm for the AR mod is one that
> mounts via a threaded pillar with a locking nut. Both
> the Mayware Formula 4 and Grace 707 Mark II meet this
> requirement. Unfortunately, my classic favorite, the
> SME 3009 Mark II Improved, does not.
>
> The springs on the I-bar subchassis are carefully
> spaced equidistance from its center of gravity. So,
> ideally, the replacement arm should be the same weight
> as the original. I found that the original tone arm
> and its spindle well (after removal) come to about 7
> oz. Ideally, the replacement arm and its mounting
> plate should come close to that figure. Another
> important specification is the tone arm length - the
> original arm has a 9" stylus to pivot length, and is
> 11 5/8" overall. You should, of course, be sure the
> counterweight of the replacement arm will clear the
> corner of the dust cover.
>
>The problem is, since the article is 15 years old, both of the
>two suggested tonearms are quite hard to find (and expensive!)
>nowadays. I'd be grateful for any suggestions for other
>suitable replacement arms, preferably cheap ones... or, at
>least ones with good value for money. :-)